153 research outputs found
Higher-order Topological and Nodal Superconductors MS (M = Nb and Ta) Transition-metal Sulfides
Intrinsic topological superconducting materials are exotic and vital to
develop the next-generation topological superconducting devices, topological
quantum calculations, and quantum information technologies. Here, we predict
the topological and nodal superconductivity of MS (M = Nb and Ta)
transition-metal sulfides by using the density functional theory for
superconductors combining with the symmetry indicators. We reveal their
higher-order topology nature with an index of Z4 = 2. These materials have a
higher Tc than the Nb or Ta metal superconductors due to their flat-band and
strong electron-phonon coupling nature. Electron doping and lighter isotopes
can effectively enhance the Tc. Our findings show that the MS (M = Nb and Ta)
systems can be new platforms to study exotic physics in the higher-order
topological superconductors, and provide a theoretical support to utilize them
as the topological superconducting devices in the field of advanced topological
quantum calculations and information technologies.Comment: 5 pages, 3 figure
The properties of horizontal magnetic elements in quiet solar intranetwork
Using the data observed by the Solar Optical Telescope/Spectro-Polarimeter
aboard the Hinode satellite, the horizontal and vertical fields are derived
from the wavelength-integrated measures of Zeeman-induced linear and circular
polarizations. The quiet intranetwork regions are pervaded by horizontal
magnetic elements. We categorize the horizontal intranetwork magnetic elements
into two types: one is the non-isolated element which is accompanied by the
vertical magnetic elements during its evolution; another is the isolated
element which is not accompanied by the vertical magnetic elements. We identify
446 horizontal intranetwork magnetic elements, among them 87 elements are
isolated and 359 are non-isolated. Quantitative measurements reveal that the
isolated elements have relatively weaker horizontal magnetic fields, almost
equal size, and shorter lifetime comparing with the non-isolated elements. Most
non-isolated horizontal intranetwork magnetic elements are identified to
associate with the emergence of Omega-shaped flux loops. A few non-isolated
elements seem to indicate scenarios of submergence of Omega loops or emergence
of U-like loops. There is a positive correlation between the lifetime and the
size for both the isolated and non-isolated HIFs. It is also found that there
is also positive correlation between the lifetime and the magnetic flux density
for non-isolated HIFs, but no correlation for isolated HIFs. Even though the
horizontal elements show lower magnetic flux density, they could carry the
total magnetic flux in the order of magnitude close to 10^25 Mx to the solar
surface each day.Comment: 10 figures, 25 pages. ApJ, in pres
Passivation mechanism of thermal atomic layer-deposited Al2O3 films on silicon at different annealing temperatures
Thermal atomic layer-deposited (ALD) aluminum oxide (Al(2)O(3)) acquires high negative fixed charge density (Q(f)) and sufficiently low interface trap density after annealing, which enables excellent surface passivation for crystalline silicon. Q(f) can be controlled by varying the annealing temperatures. In this study, the effect of the annealing temperature of thermal ALD Al(2)O(3) films on p-type Czochralski silicon wafers was investigated. Corona charging measurements revealed that the Q(f) obtained at 300°C did not significantly affect passivation. The interface-trapping density markedly increased at high annealing temperature (>600°C) and degraded the surface passivation even at a high Q(f). Negatively charged or neutral vacancies were found in the samples annealed at 300°C, 500°C, and 750°C using positron annihilation techniques. The Al defect density in the bulk film and the vacancy density near the SiO(x)/Si interface region decreased with increased temperature. Measurement results of Q(f) proved that the Al vacancy of the bulk film may not be related to Q(f). The defect density in the SiO(x) region affected the chemical passivation, but other factors may dominantly influence chemical passivation at 750°C
Reporting of ethical considerations in clinical trials in Chinese nursing journals
Background: It is acknowledged that publishers now require all primary research papers to demonstrate
that they have obtained ethical approval for their research.
Objectives: To assess the rate of reporting of ethical approval in clinical trials in core nursing journals in
mainland China.
Research design:
A retrospective observational study.
Participants:
All clinical trials published in all of the 12 core nursing periodicals from 2016 edition China
Science and Technology Journal Citation Report (core version) between 2013 and 2016 were retrieved by hand
to explicate rate of reporting ethical approval and informed consent.
Ethical considerations:
The study did not require approval from the research ethics committee as it did
not involve human subjects or records.
Results:
In total, 40,278 papers were published in 12 nursing periodicals between 2013 and 2016. Out of
these, 9488 (23.6%) focused on clinical trials. Informed consent obtained from patients or the legally
authorized representative was reported in 51.8% of clinical trials. Notably, only 27.4% of clinical trials
reported that they had obtained written consent. Furthermore, 25.9% of clinical trials described ethical
approval; however, the rate of reporting informed consent and ethical approval in these 12 nursing journals
in China during 4 years from 2013 to 2016 improved markedly, with 38.1%, 44.0%, 59.0% and 66.6%,
respectively (p<0.001), and 17.6%, 21.9%, 28.6% and 35.8%, respectively (p<0.001). In addition, both
reporting informed consent and reporting written informed consent had a positive significant correlation
with the reporting ethical approval (p<0.05 or p<0.01).
Conclusion:
Chinese scientific nursing journals have improved the rate of reporting informed consent and
ethical approval in clinical trials during the last 4 years. However, it should be noted that nearly half of clinical trials still did not report either ethical approval or whether informed consent was obtained. Efforts from
editors, researchers, sponsors and authors are needed to ensure the transparency of ethical scrutiny and
adherence to ethical guidelines in publishing clinical trials in Chinese nursing journals
Solar Intranetwork Magnetic Elements: bipolar flux appearance
The current study aims to quantify characteristic features of bipolar flux
appearance of solar intranetwork (IN) magnetic elements. To attack such a
problem, we use the Narrow-band Filter Imager (NFI) magnetograms from the Solar
Optical Telescope (SOT) on board \emph{Hinode}; these data are from quiet and
an enhanced network areas. Cluster emergence of mixed polarities and IN
ephemeral regions (ERs) are the most conspicuous forms of bipolar flux
appearance within the network. Each of the clusters is characterized by a few
well-developed ERs that are partially or fully co-aligned in magnetic axis
orientation. On average, the sampled IN ERs have total maximum unsigned flux of
several 10^{17} Mx, separation of 3-4 arcsec, and a lifetime of 10-15 minutes.
The smallest IN ERs have a maximum unsigned flux of several 10^{16} Mx,
separations less than 1 arcsec, and lifetimes as short as 5 minutes. Most IN
ERs exhibit a rotation of their magnetic axis of more than 10 degrees during
flux emergence. Peculiar flux appearance, e.g., bipole shrinkage followed by
growth or the reverse, is not unusual. A few examples show repeated
shrinkage-growth or growth-shrinkage, like magnetic floats in the dynamic
photosphere. The observed bipolar behavior seems to carry rich information on
magneto-convection in the sub-photospheric layer.Comment: 26 pages, 14 figure
Enterovirus genomic load and disease severity among children hospitalised with hand, foot and mouth disease
Reporting of ethical approval and informed consent in clinical research published in leading nursing journals : a retrospective observational study
Background: Ethical considerations play a prominent role in the protection of human subjects in clinical research. To date the disclosure of ethical protection in clinical research published in the international nursing journals has not been explored. Our research objective was to investigate the reporting of ethical approval and informed consent in clinical research published in leading international nursing journals.
Methods: This is a retrospective observational study. All clinical research published in the five leading international nursing journals from the SCI Journal Citation Reports between 2015 and 2017 were retrieved to evaluate for evidence of ethical review.
Results: A total of 2041 citations have been identified from the contents of all the five leading nursing journals that were published between 2015 and 2017. Out of these, 1284 clinical studies have been included and text relating to ethical review has been extracted. From these, most of prospective clinical studies (87.5%) discussed informed consent. Only half of those (52.9%) reported that written informed consent had been obtained; few (3.6%) reported oral consent, and few (6.8%) used other methods such as online consent or completion and return of data collection (such as surveys) to denote assent. Notably, 36.2% of those did not describe the method used to obtain informed consent and merely described that “consent was obtained from participants or participants agreed to join in the research”. Furthermore, whilst most of clinical studies (93.7%) mentioned ethical approval; 92.5% of those stated the name of ethical committee and interestingly, only 37.1% of those mentioned the ethical approval reference. The rates of reporting ethical approval were different between different study type, country, and whether financial support was received (all P<0.05).
Conclusion: The reporting of ethics in leading international nursing journals demonstrates progress, but improvement of the transparency and the standard of ethical reporting in nursing clinical research is required
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